If you have a white macbook, most likely you have heard about the problem they have with the case cracking. Luckily, Apple has come out and said that they will replace the cases. My friend took his macbook in last week to get fixed so I decided that I should go ahead and take mine in.
I arrived for my appointment (if you do not know, you have to make an appointment to meet with their tech people before going in to the store) and showed them my macbook. They asked if I was still under warranty and I told them that I bought an additional two years under Apple Care. Sadly, I must never had registered my extra warranty for it was not in their system. I started worrying that they would not fix the problem but my tech told me they would still replace the case. Yeah! From searching online it was never clear whether they would only replace the case if the macbook was still under warranty, but I now have the answer.
When I got home I looked for my Apple Care info and found the paperwork. When I went back in to pick up my macbook I brought it in and they entered it into their system so now I am official. Overall, a very painless process.